A motor vehicle may be built equipped with various emissions-control components. Such components may be necessary in order to comply with government regulations on motor-vehicle emissions. Nevertheless, some motor-vehicle operators or service technicians may attempt to disable an emissions-control component in contravention of the regulations. Similarly, a operator or service technician may attempt to remove a safety feature of a motor vehicle or a feature whose removal voids a service warranty, rental agreement, etc.
In general, the OBD system of the motor vehicle may be used to detect degradation of various motor-vehicle components, whether caused by tampering, errors in servicing, or normal wear. Detection of component degradation may trigger a response by the OBD system: setting an appropriate electronic control-system flag, illuminating a dashboard signal, and/or restricting operation of the motor vehicle. In many cases, it is desirable to delay such actions until the degradation has been detected in two or more drive cycles, for increased tolerance to false-positive detection. However, to comply with some government regulations, the OBD must be able to detect emissions-control component tampering within a single drive cycle.
Accordingly, one embodiment of this disclosure provides a method for responding to conditions detected in an on-board diagnostic unit of a motor vehicle and signaling degradation of a component of the motor vehicle. The method includes providing a first response if the conditions signal degradation of the component due to tampering, and providing a second response if the conditions signal degradation of the component not due to tampering.
The summary above is provided to introduce a selected part of this disclosure in simplified form, not to identify key or essential features. The claimed subject matter, defined by the claims, is limited neither to the content of this summary nor to implementations that address problems or disadvantages noted herein.